1) yes, the "primary action" will be rightmost, this could mean progressive, in the case of a multi-step form form, destructive in the case of process where the primary function is to delete something and constructive in the case of the final step in a single or multi-step process that creates something or finalizes a  non destructive process. 

2) they should be ordered from right to left in order of importance and frequency of use, there should only be one primary action. secondary actions should have neutral or quiet appearance. 

We will capture as many patterns and best practices in the mediawiki.ui living style guide as possible, however they will be a guide and set of best practices, and there will likely be exceptions, and places where the patterns break down. 

Without completely redesigning the bottom of the wikitext editor, the minimal mediawiki.ui version of the WTE bottom could go from 

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